NEARCTIC SAWFLIES III. Heterarthrinae: Adults and Larvae (Hymenoptera: Tenthredinidae ) JUN 1 5 1971 Technical Bulletin No. 1420 Agricultural Research Service U.S. DEPARTMENT OF AGRICULTURE Acknowledgments I thank H. H. Ross, Illinois Natural History Survey, Urbana, and M. G. Emsley, Academy of Natural Sciences of Philadelphia, Pa., for allowing examination of type specimens and providing much of the material on which this study is based. Thanks are also due the following individuals for loaning considerable study material: J. Quinlan and the late R. B. Benson, British Museum (Natural History), London; John D. Lattin and Paul Oman, Oregon State University, Corvallis; H. E. Milliron, Entomology Research Institute, Canada Department of Agriculture, Ottawa; H. E. Evans, Museum of Comparative Zoology, Har- vard University, Cambridge, Mass.; L. J. Lipovsky and A. E. Brower, Maine Forest Service, Augusta; H. D. Blocker, Kansas State University, Man- hattan; R. L. Fischer, Michigan State University, East Lansing; Kenneth Goeden, Oregon Department of Agriculture, Salem; E. L. Smith, University of California, Davis; S. Frommer, University of California, Riverside; M. Wasbauer, California Department of Agriculture, Sacramento;- Joe Schuh, Klamath Falls, Oreg. Through the kind cooperation of L. J. Lipovsky of the Maine Forest Service, Augusta, I was able to obtain series of adults and larvae and also biological information on the leaf-mining species in Maine. Other material used in this study is in the U.S. National Museum, Wash- ington, D.C. NEARCTIC SAWFLIES III. Heterarthrinae : Adults and Larvae (Hymenoptera: Tenthredinidae) By DAVID R. SMITH Technical Bulletin No. 1420 Agricultural Research Service U.S. DEPARTMENT OF AGRICULTURE Washington, D.C. Issued January 1971 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 60 cents Contents Page Hosts : 3 Systematic arrangement 4 Keys to Heterarthrinae genera 6 Keys to leaf-mining larvae of Betula and Quercus 8 Tribe Caliroini 8 Genus Endelomyia Ashmead 9 Genus Caliroa 0. Costa 12 Tribe Heterarthrini 30 Genus Heterarthrus Stephens 30 Tribe Fenusini 32 Genus Metallus Forbes 33 Genus Messa Leach 38 Genus Setabara Ross 45 Genus Profenusa MacGillivray 46 Genus Bidigitus Smith 56 Genus Nef usa Ross 57 Genus Prolatus Smith 59 Genus Fenusa Leach 60 Genus Fenella Westwood 67 Literature cited 69 Index , 83 II NEARCTIC SAWFLIES in. Heterarthrinae : Adults and Larvae (Hymenoptera : Tenthredinidae) By DAVID R. SMITH, entoTnologist, Systematic Entomology Laboratory, Agricultural Research Service The Heterarthrinae are represented in America north of Mexico by 37 species in 12 genera and three tribes. This subfamily includes some of the most economically important sawflies, such as the birch leaf miner (Fenusa pusilla (Lepeletier)), the elm leaf miner (Fenusa ulmi Sundevall), the European alder leaf miner {Fenusa dohrnii (Tischbein)), the rose-slug (Endelomyia aethiops (Fab- ricius)), and the pear-slug (Caliroa cerasi (Linnaeus)). Members of the tribes Heterarthrini and Fenusini all are leaf miners in the larval stage and may be destructive to Alnus, Betula, Crataegus, Platanus, Populus, Potentilla, Prunus, Quercus, Rubus, Salix, Ulmus, and Viola. Members of the tribe Caliroini are external feeders in the larval stage and skeletonize the leaves of Castanea, Nyssa, Prunus, Pyrus, Quercus, Rosa, and Salix. This bulletin is the first comprehensive revision of the Heter- arthrinae and is intended to provide a means for identifying the Nearctic genera and species of this subfamily. Other information may be found in the literature cited, which includes most of the pertinent literature for each taxon. The subfamily limits accepted here are those proposed by Ross {1937, 1951).^ Specimens may be keyed to this subfamily by using Ross' 1937 key to the subfamilies of Tenthredinidae. The name "Phyllotominae" was used for this subfamily at that time. Benson {1952) treated the components of this group in a different manner. His concept of the subfamily Heterarthrinae was more limited and included only the genus Heterarthrus. Caliroa and Endelomyia were included in the tribe Caliroini of the Blennocampinae, and the Fenusini were also considered a tribe in the Blennocampinae. The adults of the Heterarthrinae may be characterized as fol- lows: Vein M and Im-cu of forewing divergent; vein M meets Sc + R Sit or near junction of Rs + M and Sc + R; vein 2A and SA complete for entire length, connected to lA by oblique crossvein in Caliroini and Heterarthrini, or vein 2A and 3A partially atro- phied, leaving anal cell petiolate and vein 2A and 3A present as stub, which may be straight, curved up, or curved up and meeting ^ The year in italic after the author's name is the key to the reference in Literature Cited, p. 69. 2 TECHNICAL BULLETIN 1420, U.S. DEPT. OF AGRICULTURE lA to form small basal anal cell in the Fenusini. The wing venation of various species is shown in plates I, 1-9 ; II, 10-18 ; and III, 19-20. In general, these sawflies are small black robust species. The sawflies of the Heterarthrinae are divided into three groups, each composed of closely related genera, and here treated as the tribes Caliroini, Heterarthrini, and Fenusini. The Caliroini include two genera, Endelomyia and Caliroa, which are separated from the other tribes by the complete 2A and 3A vein of the forewing and the tarsal claw with a single outer tooth and large acute basal lobe. Heterarthrtis is the only genus in the Heterarthrini, which is a Palaearctic group with only one introduced species found in North America. This tribe is separated from the others by the complete 2A and SA vein of the forewing, the 10- or 11-segmented antenna, and the tarsal claw with two subequal outer teeth and a large acute basal lobe. The Fenusini, represented in North America by nine genera, are separated from the other tribes by the petiolate anal cell of the forewing and with only the basal stub of vein 2A and SA present. The genera in this tribe may be divided further into three groups: (1) Those genera with cell ßi closed in the hind- wing—Messa, Metallus, and Setabara; (2) those genera with cell Ri open in the hindwing, with a simple tarsal claw, and with the stub of vein 2A and SA of the forewing curved up and meeting lA to form a small basal anal cell—Fenusay Fenella, and Prolatus ; (3) those genera with cell j^i open in the hindwing, with a tarsal claw having a large acute basal lobe, and with the stub of vein 2A and SA of the forewing either straight or curved up at its apex—Profenusa, Bidigitus, and Nef usa. The larvae of the Heterarthrinae fall into three distinct groups : (1) The typically sawflylike larva of Endelomyia aethiops, an external feeder (pi. XI, 130-136). The body is neither flattened nor sluglike (or tadpolelike) in appearance. The larva of this species may be separated from other sawfly larvae by the mandi- bles, which have four truncate teeth on the ventral margin and by the presence of tubercles on the thorax, on annulets 2 and 4 of abdominal segments 1 to 8, and on terga 9 and 10. (2) The sluglike or tadpolelike larvae of Caliroa, all external feeders (pi. XI, 137-141). These larvae have an enlarged thorax with the body sharply narrowing at the base and toward the apex of the abdomen ; the head is hypognathous ; the thoracic legs are reduced in size ; and a large fleshy protuberance stems anteriorly from each prothoracic leg. (3) The small dorsoventrally flattened larvae of the Heterarth- rini and Fenusini (DIS. XII-XVIII), all leaf miners. The head is usually dorsoventrally flattened and prognathous; the thoracic legs are usually reduced, sometimes lacking tarsal claws ; various numbers of sclerotized plates are present on the venter of the body ; and the prolegs are reduced or wanting. The larvae are not well known for the Caliroa species, but they are well known for most of the leaf-mining species. Many NEARCTIC SAWFLIES III. HETERARTHRINAE 3 of the leaf-mining species have been reared and the larvae have been described in the literature. The terminology used in this revision is that of Ross (1937) and Smith (1969) for adults and that of Yuasa (1922), Lorenz and Kraus (1957), and Smith (1969) for larvae. I have examined the types of all species discussed in this bulletin except those located in Europe. Hosts The known host plants for the North American species of Heterarthrinae are as follows : Plant family and genus Insect species Salicaceae : Salix I Caliroa lobrata MacGillivray I j^^gg^ tt;ttesi7iew (Konow) ÇMessa hortulana (Klug) Populus ^ Messa leucostoma (Rohwer) IMessa populifoliella (Townsend) Betulaceae : ÍFenusa pusilla (Lepeletier) Heterarthrus nemoratus (Fallen) Messa nana (Klug) Profenusa thomsoni (Konow) Alnus Fenusa dohrnii (Tischbein) Fagaceae : ^ Caliroa fas data (Norton) Caliroa lobata MacGillivray Caliroa obsoleta (Norton) Quercus J Caliroa petiolata, new species Caliroa quercuscoccineae (Dyar) Profenusa alumna (MacGillivray) Profenusa inspirata (MacGillivray) ^Profenusa lucifex (Ross) Castanea Caliroa lorata MacGillivray Ulmaceae : Ulmus Fenusa ulmi Sundevall Platanaceae : Platanus Bidigitus platani (Burks) Cornaceae: Nyssa Caliroa nyssae, new species Violaceae : Viola Nef usa ambigua (Norton) Rosaceae : Rosa Endelomyia aethiops (Fabricius) Rubus J Metallus capitalis (Norton) \ Metallus rohweri MacGillivray Crataegus Profenusa canadensis (Marlatt) Potentilla Fenella nigrita Westwood 4 TECHNICAL BULLETIN 1420, U.S. DEPT. OF AGRICULTURE {Caliroa cerasi (Linnaeus) Caliroa liturata MacGillivray Profenusa canadensis (Marlatt) Setabara histrionica (MacGillivray) (?) Pyrus Caliroa cerasi (Linnaeus) The Caliroa species recorded on Ceanothus, Cotoneaster, and Acer by Smith (1967) are larvae only. They cannot be ascribed to a particular species. Systematic Arrangement Family TENTHREDINIDAE Subfamily HETERARTHRINAE Tribe CALIROINI Genus Endelomyia Ashmead (1) Endelomyia aethiops (Fabricius) ; British Columbia, Colorado, Connect- icut, Delaware, District of Columbia, Idaho, Illinois, Kansas, Kentucky, Maine, Massachusetts, Michigan, Minnesota, Missouri, Montana, New Jersey, New York, Ohio, Oregon, Pennsylvania, Utah, Virginia, Washington; Palaearctic; on Rosa.